Flush receptacle fitting for underfloor conduit systems



July 3, 1934. SHARP 1,965,087

FLUSH RECEPTACLE' FITTING FOR UNDERFLOOR CONDUIT SYSTEMS Filed Feb. 27, 1951 2 Sheets-Sheet l FIGJ.

BY ATTORNEY5 W km fil W L. A. SHARP FLUSH RECEPTACLE FITTING FOR UNDERFLOOR CONDUIT SYSTEMS 2 Sheets-Sheet 2 Filed Feb. 27, 1951 vlhllu ll/I114.

I be made directly at and substantially Patented: July 3, 1934 I PATENT OFFICE FLUSH BECEPTACLE FITTING FOB UNDER- FIJOOB CONDUIT SYSTEMS L. Alan Sharp, Avalon, Pa, assignor to National Electric Products Corporation, New York, N. Y., a corporation of Delaware Application February 27, 1981, Serial No. 518,652

6 Claims. (Cl. 247-28) This invention relatesto fiush receptacles for underfloor duct systems.

At the present time one of the well known underfloor duct systems now on the market utilizes conduits which are disposed below the level of the floor and embedded in the concrete. With this system it is the practice to provide necks at intervals along the conduits and these necks are adapted to receive plug shaped forms about which I the concrete is moldedin the forming of the fioor. Then when one or more service connections are desired at any point or points along the floor, one or more of these plug shaped forms is removed and replaced by a service extension 'fitting or ll standpipe. These standpipes customarily project a slight distaneeabove the fioor and in some cases objection is raised as to them and it is desired to provide in lieu thereof flush receptacle fittings which will enable a plug connection to fiush' with the floor. f

The present invention is. directed to an improved fiush receptacle which is adapted for use in connection with conduit systems of the 2 class above described and in which the receptacle itself can be placed in position in direct cooperation with" the conduit in lieu of a removed plug. Further objects of the present invention also reside in the provision of. a novel plug protecting and securing means adapted for use in connection with the above mentioned flush receptacle.

A further object of the present invention resides in the provision of an improved flush receptacle suitable for use in connection with an underfloor system of the above mentioned type which receptacle also has provisions for securing thereto a protected plug of an improved form and for alternatively securing to the fitting in lieu of the plug, a floor closure plate.

Another object of the present invention resides in the provision of a plug of improved form and with an improved relation ofparts.

Further and other objects of the present invention will be hereinafter set forth in the accompanying specification and claims and shown in the drawings which by way of illustration show what I now consider to be a preferred embodiment of the invention.

In the drawings:

Figure 1 shows a sectional view of an undera floor conduit with the improved flush receptacle interengaged therein and with the improved plug ready for insertion in the fiush receptacle:

Fig. 2 is a view taken at right angles to the view shown in-Fig. 1 but with the plug inserted in the receptacle and secured thereto;

Figs. 3 and 4 are detail views taken respectively on lines 3 3 and 44 of Fig. 1; and

Fig. 5 is a fragmentary view showing the closure plate in place in the flush receptacle.

Referring to the drawings in more detail 10 is an underfloor conduit provided with an outlet neck 11 which neck is interiorly threaded to receive a plug shaped form, such plug shaped form upon removal leaves an opening through the concrete (the concrete being designated 12, and the opening being designated 13). An underfloor system of this type is more fully described in United States patent to William C. Robinson No. 1,776,195, dated September 16, 1930. The improved receptacle will now be described.

A preferable arrangement consists in making the receptacle in two parts, generallydesignated l4 and 15. Preferably these parts are made of some suitable insulating material such as a phenolic condensation product so that they may serve not only as insulators but have sufiicient mechanical stiffness to support the parts carried thereby and any superimposed floor load. Part 14 is preferably provided with a central aperture 16 through which the conductors 17 from the duct may be passed. Part 14 is also exteriorly threaded at 18 to directly engage and be secured by the threads of the neck 11 which receive the plug shaped form. The interior of the insulating block 14 is hollowed out with a recess 19 (see Fig. 3) and within this recess there are placed a pair of metallic elements 20, 21

'(Fig. 1) which serve the dual purpose of holding screw terminals 24,25. The elements 20, 21

each have a bent over portion 26 which rests on a depressed shoulder 2'7 formed in element 14. The binding screws 24, 25 thread directly into the bent over portions 26 and being overlaid by the material of the other insulating part 15 secure the elements 20, 21 in place. The current carrying conductors of the wire 17 are fastened under these binding screw terminals 24 and 25 (see Fig. 3). Elements 20, 21 have upwardly extending portions 28 and 29 of relatively diflerent configuration, for a purpose to be hereinafter explained.

The foregoing description has now described the general construction of the lower element 14 of the flush receptacle terminal device and of the parts carried by it. It may be mentioned, however, that the plug clips 22 and 23 are preferably secured to elements 20 and 21 by riveting as indicated at in Fig. 1.

The upper block 15 will now be described. This block is provided with a threaded portion 31 and with a downwardly extending shouldered portion 32. The shouldered portion 32 fits over an unthreaded flanged part of the element 14 and centrally aligns the two elements of the device with respect to each other. Part 15 is provided with plug receiving openings 33 and 34. As shown in Fig. 4, the recess or elongated slot 33 is relatively shorter than the slot 34. This construction is adopted because it is desired to prevent crossing polarity in inserting the plug and the prong elements 35 and 36 are correspondingly relatively narrower and wider. Inasmuch as crossing of polarity is to be prevented, provision must'be made for preventing the improper assemblage of the part 15 with respect to 14, otherwise the wider slot 34 might be disposed in reverse relation in the position of the narrower slot 33. Accordingly, the interior of the element 15 is provided with distinctly different shaped recesses, one recess 38 is arcuately formed (see Fig. 3) to receive the arcuate extension 28. The other recess 39 in the element 15 is relatively straight and rectangular in configuration to receive the relatively straight extension 29. This arrangement prevents improper assemblage of 15 relatively to 14. To secure 15 relatively to 14, fastening screws 40 are provided (see Fig. 2). These fastening screws are disposed with their heads in countersunk apertures in the top of part 14 and fit into the threads of ferrules 41 which are molded into the lower block 14.

The foregoing has described the complete flush receptacle assemblage. When it is desired to apply one of these devices to the conduit the plug shaped form is removed from the conduit neck 11. The two parts 14 and 15 are separated by removing screws 40. Thereafter the wires 17 are passed through the opening 16 in part 14. The part 14 is screwed into the threaded part of the neck 11 to the position shown in Fig. 1. The wires 17 are then connected to the terminals 24 and 25 and 15 is re-assembled back upon 14. The assemblage is now complete but to finish ofl the receptacle a flanged floor ring 42 is threaded into place upon the screw threads 31 of part 15. This floor ring has a depending flange portion 43 which engages the top of the shoulder 32 as shown in Fig. 1.

In the event that immediate service is not desired at a floor receptacle the interior threads 43 of the floor ring provide for the securing of a temporary closure plate 44 in position (see Fig. 5). When a plug is to be inserted in the flush receptacle this temporary closure plate is of course first removed.

The plug construction will now be briefly described. In brief the plug connection comprises a flexible sheath carrying adjacent its lower end a block of insulating material 51 which block has secured to it a cord holder or fastener generally designated 52 and adapted to relieve the strain from the conductors and their fastenings and place the strain upon the cords coming from the cable 53. Part 52 also has fastened to it the plug prongs 35 and 36 fastening being provided by means of the binding screws 53 and 54. As fully explained in Sharp application Serial No. 498,206, filed November 26th, 1930, the sheath 50 is of yielding rubber and it is adapted to yield and bend and prevent sharp bending of the wires in the cable 53. With flush floor receptacles of this type, it is quite desirable that provision be made for waterproofing the connection and pre venting ingress of water into the flush floor receptacle itself or into the conduit below it. The flexible plug 50 forms a means for waterproofing the connection, it being of yielding rubber and serving as its own gasket. When the plug assemblage including the sheath 50 has been placed in proper position to interengage the plug prongs in the receptacle, a ring 55 is interengaged with the threads 43 of the floor flange 42 which threads previously retained the temporary closure plate in position if such plate had been utilized. The ring 55 is provided with a sheet metal element 56 which is beaded over the top and bottom of the ring 55 as shown in Fig. 1 and this sheet metal ring element loosely tits in the ring 55 and permits the threading of the ring into the flange without imparting a tendency to twist the sheath 50 when the ring is so engaged with the floor flange.

As shown in Fig. 1 the member 55 is provided with a wedging portion 56' which cooperates with a tapered or conical shaped surface 57 of the sheath 50. The engaging of the ring tightly clamps against the shoulder 58 of the sheath and thus affords a water tight seal when the plug is assembled in position (see Fig. 2). As shown in this figure, it will be noted that below the taper 57 of the flexible sheath there is a shouldered portion 58 which engages under the lower edge of the ring and this provides a tight gasket at this point. The bottom part of the resilient sheath is tightly clamped both against the shouldered part of the floor ring and against the top of part 15 so that possible leakage of water into the receptacle is prevented. The flexible sheath thus serves as its own gasket.

What I claim is:

1. A floor receptacle and a plug therefor for underfloor conduit systems, comprising in combination, insulating body portions secured together and carrying plug clips and with one insulating body directly engaging an underfloor duct, a floor ring engaging one of the insulating body portions, a plug having prongs cooperating with the plug clips, and a flexible sheath-like housing for the plug having an integral flexible flange portion and means for clamping the sheath-like housing to the floor ring whereby the flexible flange portion of the sheath itself serves as its own gasket.

2. A flush receptacle for an underfloor conduit system including a receptacle assemblage comprising two parts of insulating material, one of which is exteriorly threaded to directly engage the conduit material and which part is interiorly hollowed out to receive and support plug clips, the other part being detachably secured to the first mentioned part and being provided with plug prong receiving slots in alignment with the plug clips, said second mentioned part being exteriorly threaded to receive a floor ring, and a floor ring provided with interior threads to receive a means for securing an inserted plug in position.

3. An underfloor conduit system including a buried conduit having an interiorly threaded outlet neck and having a plug receptacle assembly directly received and supported by the neck, with one portion of the plug receptacle assembly itself provided with threads to directly engage the threads of the neck, said flush receptacle assembly including two parts both formed of insulating material, one part being provided with the exterior threads to engage the threads of the outlet neck and the other part being also provided with exterior-threads, a floor ring engaging the ring of the second mentioned part and being provided with threads for alternatively receiving a floor closure plate or a plug assemblage.

4. A floor receptacle and a plug therefor, comprising in combination a plug receptacle body provided with plug prong receiving clips, a floor ring secured to the receptacle body, a plug having prongs to cooperate with the plug clips, a flexible sheath for said plug and in which the plug is carried provided with integral flexible portions adapted for gasket-like cooperation with the floor ring, and a clamping ring cooperating both with the floor ring and the sheath for clamping the latter to the former and causing portions of the sheath itself to serve as its own gasket.

5. A combined receptacle and plug provided with a floor ring and with the plug provided with a ring engageable with the floor ring to secure the plug to the receptacle, said plug itself carrying a protecting sheath of resilient yielding material and which sheath has integral portions of yielding material clamped into watertight relation with the floor ring so that the sheath itself serves as its own gasket and prevents the leakage of water into the receptacle.

6. The invention set forth in claim 5 in which the other ring is screw threaded to the floor ring and provided with slip ring means intermediate the said other ring and sheath to provide for the rotating of the ring upon its threaded engagement with the floor ring without imparting rotation to the sheath.

L. ALAN SHARP. 

